Destruction Of Vitamin Research Articles

A STUDY OF THE DETERMINATION OF VITAMIN A BY SPECTROPHOTOMETRY AND BY PHOTOELECTRIC COLORIMETRY

A comparison has been made of the determination of vitamin A in cod-liver oils and concentrates of vitamin A by means of (a) extinction coefficient measurements at 3280 Å, and (b) photoelectric colorimetry. Both methods are shown to yield results of equal accuracy, but with cod-liver oils special precautions have to be taken in the preparation and purification of the unsaponifiable fraction. No significant difference was found between the means of the quotients, blue value/E value, for low potency cod-liver oils and those for concentrates.The estimation of vitamin A by direct spectrophotometric measurements before and after its destruction by intense ultra-violet irradiation has been investigated. The conditions are described which permitted the complete destruction of vitamin A in a concentrate with apparently no significant effect on the other absorbing constituents of the oil except carotene. The residual absorption after irradiation amounted to about 5% of the initial absorption. With cod-liver oils the values obtained by this method are 20 to 30% lower than those obtained by absorption measurements on the unsaponifiable fraction. The results obtained with the concentrate indicate that a correction may be applied which reduces the discrepancy to about 10 to 15%.

Vitamin C Nutrition in Artificial Fever

SummaryStudies of Vitamin C excretion before and after periods of artificial fever show that fever increases the Vitamin C requirement of man. Studies of Vitamin C stores in adrenals and kidneys of guinea pigs show that artificial fever increases the requirement or accelerates the destruction of Vitamin C. Since guinea pigs cannot lose Vitamin C in sweat, an increase in the physiological need for Vitamin C during fever is indicated.

The Effect of the Ripening Process on the Vitamin A Content of Cheddar Cheese

Summary Data are presented to show that no serious destruction of vitamin A occurs during the ripening of Cheddar cheese. While a measurable decrease in vitamin A potency was apparent, this loss was almost wholly compensated for by moisture losses. It appears, therefore, that a pound of Cheddar cheese purchased at the end of the usual ripening period will contain approximately the same amount of vitamin A as a pound of the original curds in spite of the fact that some destruction of the vitamin has occurred.

The destruction of vitamin a by rancid cod liver oil

1. Vitamin A was destroyed in cod liver oil as rancidity developed. 2. Vitamin A was destroyed at lower peroxide values when rancidity developed at room temperature than when it was accelerated by aeration at 100°C. 3. It is suggested that not only vitamin A, but other biological properties of oils are not equally affected by rancidity produced in different ways and at different rates, and that peroxide value may not necessarily be parallel to that of other changes which take place in an oil as rancidity develops.

The Effect of Pasteurization upon the Vitamin C Content of Milk

Summary There is no significant destruction of vitamin C in milk by the Electropure (electrical conductivity) or StamVik (flash contact) methods of pasteurization when all-aluminum equipment is used. This is probably due to: (a) a very short heating time, (b) methods of heating, (c) protection from atmospheric oxidation during heating, and (d) a minimum exposure to metals which catalyse oxidation. The finding is based upon two series of animal assays of the raw and pasteurized milk and also upon titration of the vitamin by means of 2, 6-dichlorophenolindophenol. Pasteurization of milk from the same tank either on a laboratory scale or in a commercial vat at 143−5° for 30min. resulted in a significant destruction of vitamin C. The importance of conserving the natural vitamin C content of milk during pasteurization has been indicated.

Vitamin Studies XX. The Effect of Various Methods of Pasteurization on the Vitamin B and the Vitamin G Content of Cow's Milk

Summary 1.Experiments are described in which raw certified milk, produced by the college dairy herd, was fed to rats with and without supplementation with potent preparations of vitamins B and G. 2.At three different periods during the year these experiments were repeated, at which times the raw milk was pasteurized by four methods, viz., (1) ordinary pasteurization at 62-63° C. for 30 minutes; (2) same as (1) except that pasteurization was conducted under reduced pressure; (3) same as (1) except that the milk was aerated; and (4) boiled for 10 minutes under a reflux condenser. 3.The pasteurized milks were also fed to rats in the presence and in the absence of potent preparations of vitamins B and G and comparisons were made with raw milk from which the pasteurized milks were made. 4.It was found that the raw milk contained appreciable quantities of vitamins B and G and that 3 mls. per day were sufficient to furnish at least one Sherman unit of each of the vitamins. 5.It was found that vitamin B was the limiting, factor when 3 mls. of raw milk were fed as the sole source of vitamins B and G but the data indicate that the B potency was not limited to the extent that has been reported by certain investigators. 6.It was observed that the vitamin B and G potency of the raw milk was remarkably constant throughout the year. 7.Three separate sets of experiments showed greater loss of vitamin B and vitamin G when the milk was pasteurized under diminished pressure. This was contrary to expectations and will be investigated in the near future. 8.Some loss of vitamins B and G occurred in all methods of pasteurization but less destruction occurred when milk was boiled for 10 minutes under a reflux condenser. 9.Although the maximum destruction of either vitamin B or vitamin G, as a result of any one of the four methods of pasteurization, was about 38 per cent (calculated from differences in growth response), the destruction of these vitamins under carefully controlled plant operation need not be as great as indicated above. 10.It is suggested that the relative requirements for vitamin B and vitamin G by the rat vary with the age of the rat, the evidence suggesting that the requirement for vitamin B is greater in the young rat and that the need for vitamin G seems to be greater as the rat matures.

VITAMIN A CONTENT OF MILK IRRADIATED BY VARIOUS CARBON ARCS

Enhancement of the antirachitic and calcifying properties of milk by exposure to ultraviolet rays has raised the question as to whether or not there was a destruction of vitamin A. Data from various laboratories have been contradictory, but a review of such data shows that a wide difference in the technic of irradiation, particularly in reference to the period of exposure, was in all probability the cause of the conflicting evidence. For illustration, Titus and Hughes 1 reported the apparent destruction of vitamin A in milk after an irradiation period of several minutes, whereas Supplee and Dow 2 reported that there was no measurable destruction of vitamin A after an exposure period of only sixteen seconds, during which substantial antirachitic properties were imparted to the milk. Further work on the irradiation of milk at this laboratory, 3 wherein the physical characteristics of the radiant energy have been correlated with the

Avitaminosis. VI. Vitamin B Lipemia Versus Inanition Lipemia in the Lactating Rat and its Nursing Young.

The purpose of this study was to determine the effect of a deficiency of vitamin B per se on lipid metabolism of the lactating albino rat and its nursing young. The avitaminosis was produced according to technique previously described.1 The experiments were conducted in triads. The pathological group received auto-claved dried baker's yeast as a source of vitamin G. Litter mates were restricted to the same amount of food and water of the same diet as consumed by the avitaminotic group, but the yeast in the ration was untreated. The plane of nutrition was the same in this diet, and the only limiting factor was the destruction of vitamin B in the process of autoclaving. Another group of litter mate lactating rats was fed the same ration, containing the untreated yeast, but the daily intake of food and water was unrestricted. As the only limiting factor between the second and third groups was the plane of nutrition, the difference is due to inanition.One-half a cc. of blood was used for the determination of ...

The Excretion of Vitamin B by Artificially Fed Infants.

Vitamin B in the urine and feces of animals and in human urine has been demonstrated by Muckenfuss, Van Der Walle, and Cooper. According to Cowgill the vitamin in the urine represents the amount ingested in excess of the needs of the animal, whereas that in the fecal excretion has been shown to be unabsorbed material. The presence of Vitamin B in the urine of an animal, therefore, would seem to indicate the adequacy of the diet as a source of this factor; and the amount of the vitamin excreted in the feces should give some measure of the amount not available to the organism. With such an interpretation in mind, a study of the intake and excretion of Vitamin B (the antineuritic factor) has been made on a group of 11 artificially fed infants and the retention of the vitamin determined. Thirty-three collections of urine and feces were tested. The food of all the children consisted essentially of cow's milk, a carbohydrate modifier free from Vitamin B, orange juice, and cod liver oil. In a few cases a Vitamin B containing extract was added to the feeding mixture in order to ascertain the influence of a larger ingestion. The determination of the amounts of Vitamin B in the ingested food and in the excreta was made by a biological assay on young rats of uniform weight and uniformly depleted of their vitamin stores. Each sample of the concentrated urine and dried feces was fed at various levels, from one to 6 rats being used at each level. Parallel experiments with yeast indicated no destruction of Vitamin B by the methods of concentrating and drying employed.

Fat Soluble Vitamins: XXXIII. The Determination of Vitamin a and its Stability in Butter Fat to Ultra Violet Radiations

Summary Different techniques for determination of vitamin A have been discussed. The Evans-Bishop technique was found to have no advantage over those techniques which depend upon the reinitiation of growth or the cure of ophthalmia. Of these latter the ophthalmic method was preferred, because of the specific nature of its reaction, and its rapid responsiveness. The growth method was also found reliable and correlated closely in results obtained with the ophthalmic method when the animals were taken for test shortly after growth ceased. Furthermore, with animals of variable weight we experienced difficulty in deciding just when they should be taken for the growth test. Vitamin A is destroyed by ultraviolet treatment even when the irradiation is carried out in an atmosphere of CO 2 , nitrogen, or hydrogen. However, these gases apparently do retard the destructive reaction somewhat. It is still possible that our preparations of butter fat may have contained a sufficiency of oxygen in solution to have allowed destruction by oxidation. This hypothesis appears tenable when one takes into consideration the very small amounts of vitamin A which can produce cure of ophthalmia or reinitiation of growth. The destruction of vitamin A was found to be proportional to the time of exposure and inversely proportional to the thickness of the layer of fat exposed. The irradiation necessary to secure maximum activation was found to cause some destruction of vitamin A. Practically, however, maximum activation may not be desirable from the dietetic standpoint, so that the antirachitic activation of butter fat by direct irradiation is a practical possibility without danger of destroying vitamin A. Butter fat, antirachitically activated, was found to have retained most of its vitamin A even after storage for seven months at room temperature.

Studies on the Destruction of Vitamin C in the Boiling of Milk

Studies on the Destruction of Vitamin C in the Boiling of Milk

Effect of Hydroquinone in Vitamin A Deficiency.

Since the discovery about 1913 that a lack of vitamin A in the diet would cause ophthalmia in rats, attempts have been made to show that this pathological condition might also be due to other factors than the absence of this vitamin. The so-called “salt ophthalmia” of McCullom, Simmonds and Becker, has been shown by McCullom, Simmonds and Becker and Jones to be due to an oxidative destruction of vitamin A in the diet by ferrous sulfate if the diets are not made up frequently. However, when the diet is made up daily, or every few days, no ophthalmia develops. Recently Huston and Lightbody have presented evidence to show that hydroquinone had a definite beneficial effect when used in a diet low or lacking in vitamin A. Huston, Lightbody and Ball6 also concluded that hydroquinone had a definite anti-oxygenic effect on the vitamin A of milk fat and cod liver oil. If these views are correct, a very important physiological rôle must be attributed to this phenol. In order to test out the hypothesis of Huston and Lightbody, we fed 2 groups of rats on a vitamin A free diet consisting of extracted and heated casein, 18 gm., corn starch, 51 gm., crisco, 23 gm., salt mixture (Osborne and Mendel), 5 p., dried yeast, 3 gm., with 2 drops daily of a 5% solution of Vigantol to supply vitamin D. 0.05 and 0.1 gm. of hydroquinone per 100 gm. of the above diet were fed to the 2 groups of animals from the time of weaning. This diet was made up weekly. The 11 animals of these 2 groups all lost weight, developed ophthalmia and died. When 1 part of a substance is included in 1000 parts of food the chances are very good that each animal will not receive a given amount of this small part each day. Hence a third group of rats were fed the above diet from the time of weaning and were given daily by mouth 5 drops of a solution of hydroquinone equivalent to 7 mg. of the phenol. The same results were obtained as described above. 3 animals of this group were cured of ophthalmia by cod liver oil.

Influence of Wheat Germ Oil on Fertility of Rats Fed Fat Free Rations.

In animal studies pertaining to Vitamin E, varying amounts of fat have been used as essential constituents of the ration. Certain of these are known to have a specific influence on the rate of the oxidative changes in fats carrying the vitamins A and E. For example, wheat germ oil, a substance seemingly rich in Vitamin E., has been found to retard the oxidation of cod liver oil, as well as the destruction of Vitamins A and E; whereas lard hastens the destruction of these vitamins. Correlating these findings with the results of animal experiments, one is led to wonder if wheat germ oil is effective as an antisterility agent because of the presence of a specific vitamin, or because of its retarding influence on the oxidation of Vitamin A, a certain minimum of which is necessary for reproduction. It seemed possible that this might be determined by comparing the growth and reproductive behavior of animals receiving fat free rations, with animals receiving similar rations to which were added small amounts of wheat germ oil. We therefore have fed 3 groups of rats purified rations in which the Vitamins A and D were supplied by a cod liver oil concentrate (Oscodol). Vitamin B was furnished by starch free yeast. In one group the ration was supplemented with 3% of wheat oil; in another 12 gm. of lard was substituted for 27 gm. of cornstarch. All rations were made into a paste with distilled water, fresh mixtures being prepared approximately twice a week. TWO oscodol tablets, the equivalent of about 5% of the ration in cod liver oil, were added to every 488 calories of food. This, we have reason to believe, furnished a plethora of Vitamin A.

Note on Tea as a Source of Vitamin C.

With the exception of cabbage and lettuce the leaves of plants have not been examined quantitatively for their content of vitamin C. The observations of Miura1 indicated that different kinds of tea possessed widely different amounts of vitamin C, and the quantity found in green tea compared favorably with the content of the usual anti-scorbutic foodstuffs. Fermentation and its accompanying oxidative changes are a part of the commercial processes of tea manufacture and it seemed desirable to confirm Miura's observations with the possibility of correlating the data with the accepted facts relative to the oxidative destruction of vitamin C.A series of 300 gm. guinea pigs on Sherman's2 basal ration (with equal weights of rolled oats and wheat bran) was used for curative tests. These animals gained their last 50 gm. of body weight on the basal ration plus a leaf of cabbage. After the latter was omitted scurvy developed in from 2 to 4 weeks. Due to too long a delay in initiating the curative regime some animals...

Further Evidence of Destruction of Vitamin B in Evaporated Milk.

Hartwell's1 method of determining the Vitamin B content of foods differs from that of other workers, in that it consists in measuring the effects of a given ration on the suckling young. Either just before or just following parturition the mother animal is put on a high protein ration containing all the known necessary constituents, with the exception of Vitamin B. In the absence of an adequate amount of Vitamin B the suckling young gain normally for about 13 days, when they suddenly develop convulsions, manifested by general muscular incoordination. This condition is frequently accompanied by unusual outcries, and dragging of the hind legs. The baby animal gasps for breath, and finally dies within a few hours. That these animals do not die of insufficient food is indicated by the fact that milk is very frequently found in the stomachs. When adequate amounts of Vitamin B are added to the ration the young animals develop normally and are weaned at the usual time.By this method,2 comparative studies of fres...

THE OXIDATIVE DESTRUCTION OF VITAMINS A AND E

It is generally accepted that vitamin A as found in butter fat and cod liver oil is easily destroyed. Heating and aerating these fats for a short time or exposing them to air at room temperature for a longer period uusually deprives them of every trace of vitamin A. During such treatment the fats absorb oxygen and a long series of partial oxidation products is recognized as accompanying the more or less undefined condition of rancidity so developed. A destruction of vitamin E as found in butter fat was first indicated by our experiments 1 on milk rations. These showed that 50 per cent of whole milk powder supplemented with 8 per cent of casein, 2 per cent of mineral salts, 5 per cent of yeast and 35 per cent of starch was adequate for growth and reproduction of rats, but that when appreciable quantities of lard, from 15 to

Effect of ultraviolet light on the vitamin C content of cow's milk

As is well known, in recent years, for the treatment of rickets intensively recommended feeding children with milk subjected to ultraviolet light. According to Raehr's observations (Klin. Woch., 1926, No. 50) such lighting not only significantly worsens the smell and taste of milk, but also deprives it of antiscorbutic and antirachitis properties on the grounds of destruction of vitamins C and A under the influence of significant formation of ozone.

Destruction of Vitamin A in Milk by Ultra-Violet Light

Destruction of Vitamin A in Milk by Ultra-Violet Light

INFLUENCE OF COOKING AND CANNING ON VITAMIN CONTENT

T HE CONSUMER'S interest in foods lies not so much in the measure of the rate of destruction of vitamins in a foodstuff as in the practical question of how much he must eat to secure the vitamin effect of that food. As an example of this point we may cite the cabbage of the Delf experiments in England. In her experiments, Miss Delf showed that one-thirtieth of an ounce of raw cabbage would protect a guinea pig from but that after boiling the cabbage for one hour, twenty times as much cabbage was required to produce the same effect. She stated her results in the quantitative form, i.e., that by boiling cabbage for one hour at 2120 F. we get 95 per cent destruction of vitamin C. These experiments we have confirmed. They have been used, however, in a way not intended by the investigator. Impressed by the 95 per cent, we find supposedly intelligent people making statements of this sort: Delf's experiments show that cooked foods are worthless as protection against scurvy ; Foods that are heated to boiling temperatures or higher are of no value as antiscorbutics; Canned foods which are processed at 2120 F., or at higher temperatures, are worthless as protection against scurvy, etc. Each observation fails to take into account two features of Delf's experiments, first, that 95 per cent is not 100 per cent; second, the actual quantities of cooked

A QUANTITATIVE STUDY OF THE DESTRUCTION OF VITAMIN B BY HEAT

Using the rat growth method with the system of controls and precautions developed by Dr. Edgeworth, Dr. Spohn and the authors, studies were made of the percentage destruction of vitamin B at the temperatures 100°, 110°, 120°, 130° C when in each case the heating was continued for 4 hours and the vitamin was contained in a water solution (tomato juice) at the natural acidity of the tomato juice, namely pH = 4.3.The juice of canned tomatoes was chosen as a suitable form in which to study vitamin B and for the further reason that the results here obtained would thus become directly comparable with the results of the studies, previously made in our laboratory, upon the heat destruction of vitamin C.For descriptions of methods and for experimental data and their discussion, reference must be made to the original papers in the Journal of the American Chemical Society.1 In the paper of which the present communication is an abstract the effects of different amounts of vitamin B upon the weight curve of the young ...